LVM over NFS

[congelli501]

Hi,
I can't have access to an iSCSI SAN (just NFS). So, would it be safe to :
- Create a huge file in the nfs partition (~ 500Go)
- Create a device from this file (loopback)
- Make a LVM volume using this loopback device, and use it form VMs and CTs

My cluster is made of 3 nodes.
Thanks in advance !

 

[e100]

You do not need LVM for KVM VMs
KVM disks can be stored as files too (raw or qcow2), just add your NFS storage, mark it as shared and then go create VMs.

 

[congelli501]

Thanks for your answer.

We have been using NFS for now and we want to switch to LVM for these two reasons :
- Live snapshot (we have a lot of CTs / VMs, and backup time is very long : all night).
- Performance : NFS is bad for CT since the NFS driver assumes everyone might modify the content of a VM / CT, so read cache is very limited.

 

[e100]

LVM is no longer needed to do snapshot backups with KVM vms.

 

[congelli501]

Thanks for your answer but it is still impossible to do live backup for CT, and downtime are problematic.
We also can't switch all our CT to VM as it would require much more RAM than what we have.